with the valve been shifted over to the low psi side, with that corrected iirc there was something about slightly opening the high side making it now the low side & bumping the pedal to shift the valve back the other way to center it. Not sure how holding the "pin" valve open plays out with this procedure but others will clarify. I always thought the center valve was strickly an electrical on/off switch (to warn you of a leak on the "low" side) but did not shutoff flow so I learned something on this.